Keith Spera / The Times-PicayuneA large Banksy rendering of a child flying a refrigerator kite at St. Claude Avenue and St. Anthony Street was recently painted over.

If clandestine British graffiti artist Banksy ever returns to New Orleans, I'm going to wrap my house in canvas, set his favorite snack on the porch and hope that, like Santa Claus, he shows up in the middle of the night bearing gifts.

Any little doodle will do.

Three weeks ago, around the third anniversary of Hurricane Katrina, Banksy apparently slipped into New Orleans and tagged a dozen walls with his signature style -- spray-painted, stenciled designs with a political/surrealistic/comic slant. Perhaps you've spotted the little girl flying the refrigerator kite on St. Claude Avenue or the homeless Abe Lincoln on Cleveland Avenue.

The art-versus-vandalism argument aside, Banksy's visit was the equivalent of a leprechaun dispensing pots of gold.

In February, Bonhams auction house in London hosted its first-ever "urban art" sale. A 2002 Banksy piece titled "Laugh Now" -- spray paint on wood, it depicts a row of chimpanzees with sandwich boards taunting humans -- sold for 228,000 British pounds.

A hospital worker whose husband had received a small Banksy print called "Flag" -- one of a set of 50 -- let it go for $35,000.

You get the idea.

Within the past few years, Banksy has achieved pop culture critical mass. Angelina Jolie is reportedly among his fans and collectors. And once a 200-year-old British auction house starts hawking your creations, you are no longer underground.

Keith Spera / The Times-PicayuneA gaping hole is all that remains of a silhouette rat applied by graffiti artist Banksy to an abandoned house off St. Claude Avenue.

The relative scarcity of Banksy's work, coupled with the mystique fostered by his closely guarded anonymity and prankster ways, drives up the price. That scarcity is partially a function of his preferred, extremely precarious medium: public spaces, where the unguarded art can be painted over or pried loose by passers-by.

Questions of graffiti art authenticity can be tricky, but Banksy seems to take credit for the New Orleans images via photos on his Web site. He doesn't intend for such works to be sold, especially when the provenance is murky. In 2007, eBay stopped the online sale of a stenciled Banksy rat hacked from the wall of a park in London's Paddington neighborhood.

But within days of his public art becoming public knowledge, the treasure hunt is on. It's as if Picasso dashed off a nude, propped up the canvas against a City Park oak tree and walked away. One moment, it's potentially worth a fortune. The next, it's worthless. Or gone.

The three known Banksy tags rendered on the wood facades of local abandoned houses -- a small turtle, a rat and the silhouette of a trumpet player -- have already disappeared. A gaping hole has replaced the trumpeter that briefly adorned the front of a dilapidated house at North Roman and Dumaine streets; looters cut away the entire section of peeling boards.

Larger Banksy pieces applied to cement, cinder block and brick walls are not so easily pilfered or brought to market. (And here's hoping no one attempts to "liberate" the painting on the Industrial Canal floodwall.)

But this week, the boy on a life preserver swing rendered outside a Katrina-wrecked North Claiborne Avenue barroom was defaced with red spray paint. A large mural of a boy flying a refrigerator kite on the side of a convenience store was also painted over this week. And as drivers stopped to photograph the "Rain Girl" on North Rampart recently, young men loitering nearby discussed plans to alter it.

Keith Spera / The Times-PicayuneAround Sept. 17, someone used red spray paint to deface Banksy's rendering of a boy swinging on a life preserver on the outside wall of a ruined North Claiborne Avenue barroom.

An empty building on Oretha Castle Haley Boulevard received one of the most elaborate -- and thus potentially valuable -- works, a procession of brass band musicians equipped with gas masks.

In a fit of anti-graffiti pique, and apparently unaware of the painting's pedigree, the building caretaker painted over it. Instead, he could have demolished the rest of the structure and probably sold that one wall for more than the entire building is worth.

Waking up to a Banksy on your wall is like discovering pirate Jean Lafitte's buried treasure in your backyard.

In 2002, Banksy traveled to the Leeds music festival in England to confer with the band Blur on designs for a magazine cover. A nearby farmer allowed the artist to use his farm as a sketch pad. Banksy spray-painted a design on the sheet metal door of a duck shed.

Five years later, the farmer renovated the shed. He had the good sense to consign the door to Bonhams for auction. "Untitled, TV Girl" sold for $68,000.